CVE-2021-4093

Updated: 2025-08-20 02:14:25.749573

Description:

A flaw was found in the KVM's AMD code for supporting the Secure Encrypted Virtualization-Encrypted State (SEV-ES). A KVM guest using SEV-ES can trigger out-of-bounds reads and writes in the host kernel via a malicious VMGEXIT for a string I/O instruction (for example, outs or ins) using the exit reason SVM_EXIT_IOIO. This issue results in a crash of the entire system or a potential guest-to-host escape scenario.


Links NIST CIRCL RHEL Ubuntu

Severity

Severity Score
CVSS Version 2.x HIGH 7.2
CVSS Version 3.x HIGH 8.8

Status

OS name Project name Version Score Severity Status Errata Last updated

Statement

AlmaLinux 9.2 ESU kernel 5.14.0 8.8 HIGH Already Fixed 2024-07-01 10:16:45
CentOS 6 ELS kernel 2.6.32 8.8 HIGH Not Vulnerable 2022-03-30 15:43:18
CentOS 7 ELS kernel 3.10.0 8.8 HIGH Not Vulnerable 2024-07-01 10:09:56
CentOS 8.4 ELS kernel 4.18.0 8.8 HIGH Not Vulnerable 2024-07-01 10:35:15
CentOS 8.5 ELS kernel 4.18.0 8.8 HIGH Released CLSA-2023:1690294029 2023-07-25 11:16:01
CentOS Stream 8 ELS kernel 4.18.0 8.8 HIGH Already Fixed 2024-06-09 11:20:37
CloudLinux 6 ELS kernel 2.6.32 8.8 HIGH Not Vulnerable 2022-03-30 15:43:18
CloudLinux 7 ELS kernel 3.10.0 8.8 HIGH Ignored 2025-01-10 22:43:42 CL7 support is limited
Oracle Linux 6 ELS kernel 2.6.32 8.8 HIGH Not Vulnerable 2022-03-30 15:43:18
Ubuntu 16.04 ELS linux-hwe 4.15.0 8.8 HIGH Not Vulnerable 2022-10-04 14:02:36
Total: 11